纳米金-石墨烯修饰碳糊电极微分脉冲溶出伏安法检测水中铅

构建纳米金(Au)-石墨烯(GS)修饰碳糊电极(CPE)的电化学传感器(CPE│GS/Au)，建立微分脉冲溶出伏安(DPSV)法测定痕量铅的电化学分析方法。采用扫描电镜(SEM)表征GS和电极的制备过程，采用DPSV法研究铅的电化学性质。在优化的实验条件下，溶出峰电流与Pb2+浓度在2×10-10~5×10-8 g/mL范围内呈良好的线性关系，线性相关系数为0.999 0，检出限为1.2×10-10 g/mL。用于实际水样分析，与石墨炉原子吸收光谱(GF-AAS)法所得结果一致，相对标准偏差(RSD)小于4.3%。该传感器采用复合纳米微粒修饰CPE，扩增了响应电流且一次使用可抛弃、分析成本低，具有较好的制备重复性。

Differential pulse stripping voltammetry determination of trace lead in water using Au-graphene sheets modified carbon paste electrode

A sensitive electrochemical sensor based on graphene sheets(GS) and gold nano-particles(Au) modified carbon paste electrode(CPE) was fabricated(CPE│GS/Au). An electrochemical analysis method for the determination of trace lead in water by differential pulse stripping voltammetry(DPSV) was developed using this electrode as working electrode. Different technologies were employed to study the construction processes and electrochemical properties of the sensor. Under optimum experimental conditions, the stripping peak current showed good linear relationship with Pb2+ in the range of 2×10-10-5×10-8 g/mL(R2=0.999 0) with a detection limit of 1.2×10-10 g/mL. The relative standard deviation (RSD) was below 4.3%. The analytical results were comparable with graphite furnace atomic absorption spectrometry(GF-AAS) method. The proposed CPE has high surface activity due to the modification with composite nano-particles, which could amplify the response current. It also showed the merits of disposable design, low cost and good reproducibility compared with other Pb2+ sensors.